Rolling hollow steel



Feb., 23 1926. E. BUMFORD ROLLING HOLLOW STEEL Filed NO'v. l0, 1921 Patented Feb. 23, i926.

, UNITED STATES PATENT OFFICE.

EDWARDBUMFORD, or BIRMINGHAM, ALABAM, .A

Application filed November 10, 1921. Serial No. 514,410.

To all whom #may concern:

Be it known that I, EDWARD BUMFORD, a

citizen of the United States, and resident of Birmingham, Alabama, have invented 5 certain new and useful Improvements in Rolling 'Hollow Steel, of which the following is a specification.

' In an application of Herbert C. Ryding,

filed concurrently herewith, there is described a method of producing hollow rolled bars by the use of a filling material capable' of having its physical condition changed after the rollin@ of "the bar, so as to permit its easy remova ,the invention being claimed broadly therein .and with particular reference to the use of lead as a filler.

My present invention is directedto a speciic improvement in which the' filler is of a material capable of removal by water.

For example, I may use a material 'which has a chemical reaction with water, and which by such reaction is changed to a form capable of flowing or being washed easily out of the hollow of the bar. Such a material is calcium carbide. A

An exam )le of the process using this filling materia is as follows. A billet of tool steel, say 4, x 4t inches, has -a one and onequarter inch hole drilled longitudinally in with granular carbide and plugged with a screw plug at the 'open end. It is then rolled down to a bar of the desired dimensions, cut into suitable lengths and dropped into water. The car'bide is converted by the water into with a residue of lime which is easily washed out. Or burnt lime may be used as a filler; and can be easily removed by solution and washing with water afterwards.

it to within .an inch of the end, and filled` .the following claim.

Various other compositions are capable of being used in the same way.

In the accompanying drawings Fig. l is a diagrammatic view of a billet having-a longitudinal bore, d, which is closed at one end by a screw block, P, and at the opposite end by the inte ral end wall.l fw, of the billet. The bore o the billet is filled with a suitable material, C, which is adapted to have its form changed by reaction with water so that it can be readily washed out after the billet has been rolled to the required size.

Fig. 2 shows the condition of the billet after it has been subject to the action of the rolls in a suitable rolling mill. The dotted lines indicate 'the lengths to which the rolled tube may be cut prior to washing the filling out by subjecting it to the action of the water as above described.

Though I have described with great particularity of detail a certain embodiment of my invention, yet it is not to`be understood therefrom that the invention is restricted to the particular embodiment disclosed. 05 Various modifications in detail and in the composition and treatment of the filler may be made by those skilled in the art without departure from the invention as defined in What I claim isz. The method of producing hollow rolled bars which comprises providinga hollow blank filled with calcium carbide, rolling the bar and' removing the carbide with the 75 aid of water. In witness whereof, I have hereunto signed my name.

EDWARD BUMFORD, 

